When a PON (passive optical network) is accessed, an OLT (optical line terminal) at a central office is corresponding to more than one ONU (optical network unit) or ONT (optical network terminal). Because an ONT may be regarded as a special ONU, the ONU is uniformly used in the following in this specification.
In a downlink direction, downlink information of the OLT is uniformly sent to all ONUs through a fixed downlink optical wavelength; and in an uplink direction, all ONUs emit light at a specific timeslot according to a rule of an uplink optical channel bandwidth of time division multiplexing. That is, the ONU emits uplink light according to a bandwidth allocation indication of the OLT. However, a rogue ONU is an ONU that emits light not according to the bandwidth allocation indication of the OLT.
There are many kinds of rogue ONUs. From the perspective of light emission time of rogue ONUs, rogue ONUs may be divided into: persistent-emission rogue ONUs: ONUs that emit light anytime; and non-persistent rogue ONUs: ONUs that emit light in a time segment that is not indicated by the OLT, namely, ONUs that may emit light beforehand or may be shut down in delay.
As regards whether a rogue ONU accepts control of an OLT, rogue ONUs may be divided into malicious rogue ONUs: rogue ONUs that do not respond to a control command of the OLT; and non-malicious rogue ONUs: rogue ONUs that respond to the control command of the OLT.
As regards whether a rogue ONU is pre-configured, rogue ONUs may be divided into pre-configured rogue ONUs: rogue ONUs that are added through a network management system or a command line and have worked properly, and are legal ONUs; and illegally accessing rogue ONUs: rogue ONUs that are not approved by an administrator and are newly accessing ONUs, and are also called rogue ONUs in an automatic discovery state.
Currently, at the time of detecting a rogue ONU, an OLT needs to open an uplink empty window first (namely, commands all ONUs not to emit light) to detect whether a rogue ONU exists. If a rogue ONU exists, the OLT instructs all ONUs to power off their own optical module, and then powers on an optical module of each ONU one by one and opens an uplink empty window for each ONU to separately detect and determine which ONU is a rogue ONU.
In the process of implementing the present invention, the inventor finds that the prior art has at least the following problems:
With the foregoing detection method, an uplink empty window needs to be opened for all ONUs one by one for detection, and detection efficiency is lower; and at the time of detection, transmission power supply of ONUs need to be shut down one by one, thus affecting an uplink service of an ONU.